In general, there is no cure for allergies, but there are several types of medications available -- both over-the-counter and prescription -- to help ease and treat annoying symptoms like congestion and runny nose. These allergy drugs include antihistamines, decongestants, combination drugs, corticosteroids, and others.
Immunotherapy in the form of allergy shots or pills under the tongue, which gradually increase your ability to tolerate allergens, are also available.
Antihistamines have been used for years to treat allergy symptoms. They can be taken as pills, liquids, nasal sprays, or eye drops. Over-the-counter (OTC) antihistamine eye drops can relieve red itchy eyes, while nasal sprays can be used to treat the symptoms of seasonal or year-round allergies.
Examples of Antihistamines:
- Over-the-counter: Cetirizine (Zyrtec), fexofenadine (Allegra), levocetirizine (Xyzal), and loratadine (Alavert, Claritin) are taken by mouth. Brompheniramine (Dimetapp allergy, Nasahist B), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), and diphenhydramine (Benadryl) can make you drowsy. Ketotifen (Zaditor) and naphazoline and pheniramine combination ophthalmic (OcuHist) are eye drops.
- Prescription: Desloratadine (Clarinex) is a medication taken by mouth. Azelastine nasal (Astelin) is a nasal spray. Eye drops include azelastine ophthalmic (Optivar), epinastine ophthalmic (Elestat), and olopatadine ophthalmic (Patanol).
How Do Antihistamines Work?
When you are exposed to an allergen -- for example, ragweed pollen -- it triggers your immune system. People with allergies have an exaggerated immune response. Immune system cells known as mast cells release a substance called histamine, which attaches to receptors in blood vessels, causing them to enlarge. Histamine also binds to other receptors causing redness, swelling, itching, and changes in secretions. By blocking histamine and keeping it from binding to receptors, antihistamines prevent these symptoms.
What Are the Side Effects of Antihistamines?
Many older over-the-counter antihistamines cause drowsiness. Newer antihistamines that don’t make you drowsy are available over-the-counter and by prescription. Because some antihistamines can slow your reaction time, make it hard to focus or think clearly, and may cause mild confusion even if you don't feel drowsy, they may affect your ability to drive a car or operate heavy machinery.
Other side effects of antihistamines may include:
- Dry mouth
- Blurred vision
- Difficulty peeing
- Feeling tired
Decongestants relieve congestion and are often prescribed along with antihistamines for allergies. They can come in nasal sprays, eye drops, liquids, and pills.
Nasal spray and eye drop decongestants should be used for only a few days at a time because long-term use can make symptoms worse. Pills and liquid decongestants can be taken longer safely.
Examples of OTC Decongestants:
- Pseudoephedrine (Sudafed tablets or liquid)
- Phenylephrine (Neo-Synephrine) and oxymetazoline (Afrin) nasal sprays
- Some Visine eye drops
How Do Decongestants Work?
During an allergic reaction, tissues in your nose may swell in response to contact with the allergen. That swelling makes fluid and mucus. Blood vessels in the eyes can also swell, causing redness. Decongestants work by shrinking swollen nasal tissues and blood vessels, relieving the symptoms of nasal swelling, congestion, mucus secretion, and redness.
What Are the Side Effects of Decongestants?
Decongestants may raise blood pressure, so they typically are not recommended for people who have blood pressure problems or glaucoma. They may also cause insomnia or irritability and restrict urinary flow.
Other possible side effects include:
- Irritation of the lining of your nose
- Dry mouth
- Heart palpitations
Combination Allergy Drugs
Some allergy drugs contain both an antihistamine and a decongestant to relieve multiple allergy symptoms. Other drugs have multiple effects aside from just blocking the effects of histamine, such as preventing mast cells from releasing other allergy-inducing chemicals.
Examples of Combination Allergy Medicines:
- Over-the-counter: cetirizine and pseudoephedrine (Zyrtec-D), fexofenadine and pseudoephedrine (Allegra-D), diphenhydramine and pseudoephedrine (Benadryl Allergy and Sinus), loratadine and pseudoephedrine (Claritin-D), and pseudoephedrine/triprolidine (Actifed) for nasal allergies; and naphazoline/pheniramine (Naphcon A) for allergic conjunctivitis
- Prescription: acrivastine and pseudoephedrine (Semprex-D) for nasal allergies; azelastine/fluticasone (Dymista) combines a steroid in a nasal spray for seasonal nasal allergies
Anticholinergic Nasal Sprays
The drug ipratropium bromide (Atrovent) can reduce runny nose. When sprayed into each nostril, it lessens mucus from the glands lining the nasal passages.
What Are the Side Effects of Anticholinergic Nasal Sprays?
They may cause a very dry nose, leading to nosebleeds or irritation. Other side effects include headaches, stuffy nose, upset stomach, and sore throat.
Steroids, known medically as corticosteroids, can reduce inflammation associated with allergies. They prevent and treat nasal stuffiness, sneezing, and itchy, runny nose due to seasonal or year-round allergies. They can also decrease inflammation and swelling from other types of allergic reactions.
Steroids are available in various forms: as pills or liquids for serious allergies or asthma, locally acting inhalers for asthma, locally acting nasal sprays for seasonal or year-round allergies, topical creams for skin allergies, or topical eye drops for allergic conjunctivitis. In addition to steroid medications, your doctor may decide to prescribe additional types of medications to help combat your allergic symptoms.
Steroids are highly effective drugs for allergies, but they must be taken regularly, often daily, to be of benefit -- even when you aren't feeling allergy symptoms. In addition, it may take 1 to 2 weeks before the full effect of the medicine can be felt.
Exapmples of Steroids:
- Prescription nasal steroids: beclomethasone (Beconase, Qnasl, Qvar), ciclesonide (Alvesco, Omnaris, Zetonna), fluticasone furoate (Veramyst), and mometasone (Nasonex)
- Over-the-counter nasal steroids: budesonide (Rhinocort Allergy), fluticasone (Flonase Allergy Relief), and triamcinolone (Nasacort Allergy 24HR)
- Eye drops: dexamethasone ophthalmic (Maxidex) and loteprednol ophthalmic (Alrex)
- Oral steroids: prednisone (Deltasone)
What Are the Side Effects of Steroids?
Steroids have many potential side effects, especially when taken for a long time.
Side effects of systemic steroids with short-term use include:
- Weight gain
- Fluid retention
- High blood pressure
Side effects with long-term use include:
- Growth suppression
- Cataracts of the eyes
- Bone-thinning osteoporosis
- Muscle weakness
Side effects of inhaled steroids may include cough, hoarseness, or fungal infections of the mouth.
Mast Cell Stabilizers
Mast cell stabilizers treat mild to moderate inflammation.
Mast cell stabilizers are available as eye drops for allergic conjunctivitis and nasal sprays for nasal allergy symptoms. Like with many drugs, it may take several weeks before the full effects are felt.
Examples of Mast Cell Stabilizers:
- Cromolyn sodium (Opticrom)
- Lodoxamide-tromethamine (Alomide)
- Nedocromil (Alocril)
- Pemirolast (Alamast)
How Do Mast Cell Stabilizers Work?
Mast cell stabilizers prevent the release of histamine from mast cells (cells that make and store histamine). Some of these drugs also have important anti-inflammatory effects, but typically they are not as effective as steroids.
What Are the Side Effects of Mast Cell Stabilizers?
Throat irritation, coughing, or skin rashes sometimes happen. Mast cell stabilizers in the form of eye drops may cause burning, stinging, or blurred vision.
Leukotriene modifiers treat asthma and nasal allergy symptoms. They can be prescribed along with other drugs.
These medications are available only with a doctor's prescription and come as pills, chewable tablets, and oral granules.
The only leukotriene modifier that has FDA approval to treat allergic rhinitis is montelukast (Singulair). Montelukast, as well as zafirlukast (Accolate) and zileuton (Zyflo), are also FDA-approved to treat asthma.
How Do Leukotriene Modifiers Work?
Leukotriene modifiers block the effects of leukotrienes, chemicals produced in the body in response to an allergic reaction.
What Are the Side Effects of Leukotriene Modifiers?
Side effects of these drugs are rare but may include:
- Stomach pain or stomach upset
- Stuffy nose
Other Over-the-Counter Products
Some simple over-the-counter products can help with allergy symptoms. They include:
- Saltwater solution, or saline, is available as a nasal spray to relieve mild congestion, loosen mucus, and prevent crusting. These sprays contain no medicine.
- Artificial tears, which also contain no medicine, are available to treat itchy, watery, and red eyes.
Immunotherapy may be one of the most effective forms of treatment if you suffer from allergies more than 3 months of the year. Allergy shots expose you to gradually increasing levels of the offending allergen to help your immune system build tolerance.
The FDA has approved several under-the-tongue immunotherapy tablets that can be taken at home. The prescription tablets, called Grastek, Oralair, and Ragwitek, treat hay fever and work the same way as shots. The goal is to boost a patient’s tolerance of allergy triggers. Odactra is an under-the-tongue medication that can relieve symptoms of allergies to dust mites. Palforzia treats peanut allergy.
American Academy of Allergy, Asthma and Immunology.
News release, FDA.
News release, Sanofi-aventis U.S.
UpToDate.com. “Patient information: Allergic rhinitis (seasonal allergies) (Beyond the Basics),” "Oral and sublingual immunotherapy for allergic rhinitis."
RxList: "Atrovent HFA."
American College of Allergy, Asthma, & Immunology: "Allergy Treatment," "Sublingual Immunotherapy."
Cleveland Clinic: "Leukotriene Modifiers."